In the fabrication and assembly of semiconductor packages, an integrated circuit chip or die is attached to a lead frame with adhesive and wire bonding, and the die and inner lead frame assembly encapsulated in a molding resin. After encapsulation, the outer leads of the lead frame are attached to a printed circuit board or other external device. Any exposed metal surfaces, particularly copper, on lead frames or printed wire boards are subject to oxidation with exposure to air and are routinely coated with antioxidants. However, the presence of antioxidants is suspected of interfering with the bonding process during the die attach, wire bonding, encapsulation, and final soldering operations in the manufacture of the semiconductor package and its attachment to a printed circuit board.